US 11,348,746 B2 · Scissor plate control system and method for slower magnetic force decay

Abstract

An electro-permanent magnet key assembly may comprise an electro-permanent magnet generating a magnetic field when a direction of current applied to an electrically conductive wire coiled around a low-coercivity magnet, and a pair of scissor plates operably connected to the electropermanent magnet, such that the scissor plates rotate away from one another in the presence of downward force on a key cap situated atop the scissor plates. The top surface of the key cap may lie flush with adjacent keys of a keyboard when the key cap is in a neutral position. The electro-permanent magnet key assembly may further comprise a ferromagnetic flange operably connected to one of the scissor plates having angled overlap protrusions situated adjacent to the electropermanent magnet when the key cap is not in the neutral position, such that the angled overlap protrusions are attracted toward the magnetic field to return the key cap to the neutral position.

Claims20

Dependent claims

An electro-permanent magnet key assembly of an information handling system comprising:

an electro-permanent magnet (EPM) having a low-coercivity magnet and a high-coercivity magnet, wherein a magnetic field is generated by the EPM depending on a direction of current pulse applied to an electrically conductive wire coiled around the low-coercivity magnet;
a pair of scissor plates operably connected to the EPM such that each of the pair of scissor plates may rotate away from one another in the presence of downward force on the pair of scissor plates;
a key cap situated atop the pair of scissor plates such that downward force on the key cap causes the scissor plates to rotate away from one another, wherein a top surface of the key cap may lie flush with remaining keys of a keyboard when the key cap is in a neutral position;
and
a flange comprised of ferromagnetic material operably connected to one of the scissor plates having one or more angular overlap protrusions situated adjacent to a portion of the EPM, such that the one or more protrusions are attracted by the magnetic field of the EPM to return the key cap to the neutral position.

2 more elements

A method of controlling an electro-permanent magnet key assembly of an information handling system comprising:

applying a first pulse of current in a preset direction of current to an electrically conductive wire coiled around a low-coercivity magnet of an electro-permanent magnet (EPM), such that a magnetic field generated by the low-coercivity magnet combines with a magnetic field generated by a high-coercivity magnet of the EPM to generate a combined EPM magnetic field for an on state of the EPM;
and
the combined EPM magnetic field pulling a flange comprised of ferromagnetic material having one or more angular overlap protrusions situated adjacent to a portion of the EPM, such that the one or more protrusions are attracted by the magnetic field of the EPM and operably connected to one of a pair of scissor plates toward the EPM, such that the pair of scissor plates moves from a depressed position in which the pair of scissor plates are rotated away from another by a maximum allowable angle, to a neutral position in which the top surface of a key cap situated atop the pair of scissor plates lies flush with other keys of a keyboard surface.

An electro-permanent magnet key assembly of an information handling system keyboard comprising:

an electro-permanent magnet (EPM) having a low-coercivity magnet and a high-coercivity magnet, wherein a magnetic field is generated by the EPM when a direction of current pulse applied to an electrically conductive wire coiled around the low-coercivity magnet;
a pair of scissor plates operably connected to the EPM such that each of the pair of scissor plates may rotate away from one another in the presence of downward force on the pair of scissor plates;
a key cap operably coupled atop the pair of scissor plates such that downward force on the key cap causes the scissor plates to rotate away from one another, wherein a top surface of the key cap may lie flush with remaining keys of a keyboard when the key cap is in a neutral position;
a flange comprised of ferromagnetic material operably connected to one of the scissor plates having one or more angular overlap protrusions situated adjacent to a side portion of the EPM, such that the one or more angular overlap protrusions are attracted by the magnetic field of the EPM to return the key cap to the neutral position;
and
a sensor operably connected to the electro-permanent magnet key assembly transmitting an indicator to an operably connected processor that the key cap has been depressed when the scissor plates are rotated away from one another.

3 more elements

Dependencies are inferred from the claim text.

Scissor plate control system and method for slower magnetic force decay

Life of this patent

Scissor plate control system and method for slower magnetic force decay

Life of this patent

Abstract

Claims20